<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            border: 5px solid #000;
        }

        .d1 {
            background-color: #f00;
        }
        .d1:hover {
            transform: scale(0);/*缩小到看不见,并不会释放布局空间*/
        }

        .d2 {
            background-color: #0f0;
        }
        .d2:hover{
            display: none; /*会释放原有的布局空间*/
        }

        .d3 {
            background-color: #00f;
        }
    </style>
</head>
<body>
<div class="d1"></div>
<div class="d2"></div>
<div class="d3"></div>
</body>
</html>